How severe is GHSA-pwf7-47c3-mfhx?

GHSA-pwf7-47c3-mfhx has a CVSS score of 9.9/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by GHSA-pwf7-47c3-mfhx?

GHSA-pwf7-47c3-mfhx affects the following packages: j178/prek-action (GitHub Actions). Ecosystems affected: GitHub Actions.

How do I fix GHSA-pwf7-47c3-mfhx?

Update j178/prek-action to 1.0.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-pwf7-47c3-mfhx is resolved across your whole dependency graph.

How do I detect GHSA-pwf7-47c3-mfhx in my GitHub Actions dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for j178/prek-action, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-pwf7-47c3-mfhx if there is no patch (or I can't update yet)?

Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Is GHSA-pwf7-47c3-mfhx actively exploited in the wild?

No public exploit code has been indexed for GHSA-pwf7-47c3-mfhx yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was GHSA-pwf7-47c3-mfhx published, and has it been updated?

GHSA-pwf7-47c3-mfhx was published on September 29, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦

📦 GitHub Actions

Not in CISA KEV

CRITICAL severity

j178/prek-action vulnerable to arbitrary code injection in composite actionGHSA-pwf7-47c3-mfhx

CRITICALFix: j178/prek-action@6b7c6ef

GHSA-pwf7-47c3-mfhx is a critical-severity (CVSS 9.9) remote code execution vulnerability in j178/prek-action. A fix is available for j178/prek-action — see the affected versions and patch details below.

Published

Sep 29, 2025

Updated

Sep 29, 2025

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 29, 2025 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

📦j178/prek-action

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects GitHub Actions packages — download data is not available via public APIs for these ecosystems.

Description

Summary

There are three potential attacks of arbitrary code injection vulnerability in the composite action at action.yml.

Details

The GitHub Action variables inputs.prek-version, inputs.extra_args, and inputs.extra-args can be used to execute arbitrary code in the context of the action.

PoC

- uses: j178/[email protected]
  with:
    prek-version: $(printenv >> $GITHUB_STEP_SUMMARY && echo "0.2.2")
    extra_args: '&& echo "MY_SECRET with a character is: ${MY_SECRET:0:1}a${MY_SECRET:1}" >> $GITHUB_STEP_SUMMARY && echo ""'
  env:
    MY_SECRET: ${{ secrets.MY_SECRET }}

The previous example will print all the environment variables, and it will expose MY_SECRET environment variable value to the summary of the workflow. An attacker could potentially use this vector to compromise the security of the target repository, even passing unnotice because the action will run normally.

Impact

Critical, CWE-94

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦GitHub Actions	`j178/prek-action`	all versions	1.0.6

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for j178/prek-action, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update j178/prek-action to 1.0.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-pwf7-47c3-mfhx is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Frequently Asked Questions

### Summary There are three potential attacks of arbitrary code injection vulnerability in the composite action at _action.yml_. ### Details The GitHub Action variables `inputs.prek-version`, `inputs.extra_args`, and `inputs.extra-args` can be used to execute arbitrary code in the context of the action. ### PoC ```yaml - uses: j178/[email protected] with: prek-version: $(printenv >> $GITHUB_STEP_SUMMARY && echo "0.2.2") extra_args: '&& echo "MY_SECRET with a character is: ${MY_SECRET:0:1}a${MY_SECRET:1}" >> $GITHUB_STEP_SUMMARY && echo ""' env: MY_SECRET: ${{ secrets.MY_SECR

O3 Security · Impact-Aware SCA

Is GHSA-pwf7-47c3-mfhx in your dependencies?

Find it across GitHub Actions, including transitive dependencies.

Scan my dependencies How O3 SCA works